Clamps which embody these features are well known and are in common use, frequently being known as "cramps" or "carpenter's clamps", and examples of such clamps can be seen in the U.S. Pat. Nos. 237,431 (1881) Colt; 248,949 (1881) Pope; 674,278 (1901) McNutt.
One object of this invention is to provide improvements in clamps of this type which will be particularly useful in facilitating the clamping of materials, including materials which are not flat, and which will be inexpensive in its production.
There is frequently a need to use clamps of the abovementioned type for the clamping together of round material to flat material, round material to round material, and other combinations for which the existing clamps are not suitable. Because of the large angle of tilt of the sliding arm, clamps as presently used employ a swivel jaw thereon, but the swivel jaw frequently frictionally engages the screw threaded clamping means and makes it difficult to clamp two workpieces together without dislodgement, and another object of this invention is to provide improvements wherein it is unnecessary for either jaw to swivel.
If provision of a swivel jaw is not made on a prior art clamp, one jaw will tilt excessively with respect to the other upon tightening of the clamp, resulting in uneven pressures if applied to a flat workpiece, and a further object of this invention is to provide improvements wherein the tilting is reduced to insignificant proportions.